This is the standard network configuration mode utilized for Wi-Fi® networks.
- Uses Access Points (AP)
- Nodes can only transmit to other nodes through the AP
- AP fully supports all 802.11 network management functions and operations
- Basic Service Set (BSS) (aka “cell”) in Infrastructure mode contains:
- Access points
- Wireless hosts
- LAN connection (second PHY)
- No Access Points
- Nodes can only transmit to other nodes within link coverage
- Nodes organize themselves into a network of peer-peer connections
- Independent Basic Service Set (IBSS) (aka “cell”) in Ad Hoc mode contains:
- Wireless hosts only
- Distributed management
- Each station searches for a IBSS before starting it’s own (best practice – not mandated by 802.11)
- Each station takes turns transmitting the beacon for the IBSS
- Each station applies security to communications
Due to the computational/protocol overhead of current Wi-Fi® security frameworks (i.e. WPA/2), most stations in Ad-Hoc mode only implement WEP (the original 802.11 security framework), which is known to be easily broken.
For this reason, 802.11 Ad-Hoc mode is unsupported in some systems (Android for example). This has lead to the development of alternative configurations for implementing point-point Wi-Fi® communications, such as Wi-Fi Direct or Soft-AP.